How do I upgrade my weapon?

At the mission select screen, before heading into the mission, tap the 'CUSTOMIZE' button located in the bottom left of the screen

The first screen within the 'CUSTOMIZE' menu displays your Rifles. You'll notice a bar of tabs along the bottom of the screen such as RIFLES, MACHINE GUNS, SHOTGUNS, PISTOLS, GEAR, and PERKS.

First, select the category of weapon that you'd like to upgrade.

From the list that appears, slide the screen left/right until the weapon that you'd like to upgrade is visible on-screen.

Tap on the image of the weapon you want to upgrade.

The following screen displays each weapon part that can be upgraded, such as:

Range

Thermal

Zoom

Recoil

Damage

Magazine

Accuracy

Tap on the weapon part that you wish to upgrade, in this example we'll be upgrading the Magazine.

Tap on 'MAGAZINE'

The next screen displays your current magazine size and the cost in 'Cash' or 'Gold' required for the upgrade, as well as the result of the upgrade (in this case an increase in magazine size).

If you choose to upgrade using 'Cash', then there are two things to keep in mind, the cost in 'Cash' and the 'Time' required for the upgrade to complete (occasionally upgrade times for 'Cash' will be instant).

If you choose to upgrade using 'Gold' then all upgrades will be instant.